Jam-free power mechanism for typewriters



Nov. 28, 1950 R. v. REPPERT JAM-FREE POWER MECHANISM FOR TYPEWRITERS Filed Dec. 18, 1947 INVENTOR RV REPPERT gww ATTO R N EY Patented Nov. 28, 1950 JAM-FREE BOWER MECHANISM FOR.

TYPEWRITERS v Richard V. Reppert, Rochester; N. Y., assignor to International Business Machines Corporation, New York, NaYi, a corporation of New York Application December 18, 1947, Serial No. 792,535

10 Claims.

- This invention relates to typewriting machines and more particularly to typewriting machines of the type wherein the type bars and other instrumentalities are operated by power mechanism controlled by suitable keys.

- The broad object of the present invention is to provide a power mechanism in which strains put upon the power operating mechanism in consequence of jamming of the type bars or other instrumentalities operated by the power mechanism are relieved without damage to the power mechanism or anything operated thereby. An object is to provide a power mechanism which is comparatively simpler and less subject to breakage or derangement than power mechanisms hitherto known in the art.

An object is to provide a strain relieving mechanism suitable for use in power operated typewriters and similar machines in which strains are relieved automatically without the necessity for resetting any part after the condition which has caused a jam has been removed.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawing, which discloses, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

The drawing shows a diagrammatic view in vertical section of a power mechanism constructed in accordance with the present invention.

For the purposes of illustration, the power mechanism is shown in the drawing as operating a conventional type bar, but it will be understood that other devices or instrumentalities of a typewriting or similar machine may be operated by the power mechanism herein disclosed, and it is not desired to limit the invention to either the specific form of operated mechanism shown or to use of the disclosed invention in a typewriting machine.

A conventional type bar It is disclosed which is one of a plurality pivoted on the usual curved pivot wire I l whereby the type bar l may be swung in an arc of approximately 90 to strike the platen 12, it being understood that a suitable ribbon is provided through which the impressions are made on a work sheet wrapped around the platen [2. The type bars l0 may be provided with the usual rebound toggles like l3, one link of which is pivoted to the type bar at I00. while the other link is pivoted to a curved 'p'ivot wire l4 which is fixedly mounted in the frame work. The toggle link which is connected to the type bar I0 is provided with a link. l5 connecting said toggle link to the sub-lever I6 pivoted on the horizontal rod I? which also pivotally mounts the character keys l8 of which,

only one is shown. The keys are guided at their front ends in the customary key guide comb l9 and are restored by means of springs 20. The foregoing mechanism is conventional and in variant forms may be found in everytypewriter. For the purpose of operating the type bars [I] under control of the keys [8, there is provided a power mechanism which includes a common actuator, which may take the form of a fluted driving member 2! shaped in cross section like a ratchet or reamer having fourteeth or ribs, normally rotating in the counter-clockwise direction when the machine is in operation. Mounted above the power actuator or reamer 2i and extending parallel thereto a spaced distance therefrom is a supporting bar 22 which is longitudinally slotted to support a pivot wire or rod 23 and is transversely slotted at regular intervals to receive curved arms like the arm. 24 which are guided by means of a comb plate 25 secured to the bar 22. The rod 23 is held in the longitudinal slot in the bar 22 by means of a comb 26 formed with the horizontal teeth 26a ex tending between the arms 24 to space them on the rod 23 and also support the rod.

The arms 24 are connected by links 21 to arms of the sub-levers 56 whereby rocking of the arms 24 in a counterclockwise direction will draw down the links 21 and operate the type bars It! by rocking the sub-levers l6 in a clockwise direction. Suitable springs 28 restore the arms 24, the sublevers l6, and the type bars It after each printing operation. Pivotally mounted at 24a on the arm 2 is a coupling lever 29 one arm of which rotatably supports a star wheel 39 having four teeth. The star wheel is pivotally mounted in the space between the arm of lever 29 and a mounting strap 2911 which may be riveted to the side of the arm 29. The arm 25 is provided with a bent-over lug 24b to which is riveted a fiat spring finger 3! which normally presses against two of the teeth of the star wheel 30 to hold the star wheel in the position shown in the drawing. The spring 31 has considerable tension so that normally it requires considerable force to rotate the star wheel 30. The arm 2% of lever 29 engages the end of the horizontal arm of a bell crank 32 pivoted at 240' on the arm 24 and is normally held against the end of the horizontal arm of hell crank 32 by a spring 33. A spring 34 anchored to the other arm of the bell crank 32 and the arm 24 holds the horizontal arm of the bell crank 32 against a stop pin 24d carried by the arm 26. The key I8 is provided with an extension 181a carrying a finger 35 which normally is urged in a counterclockwise direction against a stop lug lilo on finger [do by a spring l8d.

For the purpose of controlling the duration of the power strokes both individually and collectively, there is provided a transverse'b'ar 36, both ends of which may be adjustably pivotally mounted as at 35a in the machine framework. The bar 36 is longitudinally slotted to receive a pivot rod 31 and is transversely slotted to receive the individual control fingers 38. For each finger 38 there is provided a pair oi adjusting screws 39 located on opposite sides of the pivot 31 by means of which the control fingers 38 may be adjustably rocked on the pivots 37 and the whole bar 36 may be adjustably rocked on the pivots 36a; by any suitable means.

When a key I8 is depressed, the extension Isa moves rearwardly or to the left in the drawing, thereby, through the finger 35, rocking the bell crank 32 counterclockwise to disengage'its horizontal arm from the arm 29b, allowing: the spring 33 to rock the arm 29 counterclockwise. This places the tooth 30a of the star wheel 38 in the path of one of the teeth Zla of the actuator 2|. Inconsequence of this, the lever 29 will be drawn to the right, rocking the arm 24 counterclockwise and, through the link 21, operating the related type bar ill. Ultimately, the right-hand end of the arm 29 will engage the lower edge of one of the fingers 38 which edge will act like a cam and gradually disconnect the tooth'SDa from the tooth 2la. The aforesaid movement of disengagement will be effected by a clockwise rotation of the lever 29 which will restore the arm 2% to latching relation with the bell crank 32, followed by the restoration of the arm 24 by means of the spring 28. The points at which the arms 29 and the star wheels 30a are disengaged from the actuator 2| will be determined by the individual angular adjustments of the fingers 38. Thus, the blows of individual type bars may be regulated and, by rocking the bar 36 on its pivots 33a, the blows of all of the type bars may be regulated collectively as for the purpose of making carbon copies or stencils.

If it should happen that the type bar Ill becomes obstructed, as by jamming with other type bars before the star wheel30a is disengaged from the actuator 2| by the finger 38, further counterclockwise movement of the arm 24 will be blocked. Under these conditions the star wheel 39a will merely rotate on its pivot and flex the spring 31 The rotation of the star wheel will also effect a rotation of the lever 29 in a clockwise direction and restore the arm 2% to latching relation with the bell crank 32 thereby preventing any harm to the mechanism. At the same time the mechanism will be automatically restored to normal condition by spring 28 except for freeing of the type bar ID, if necessary. It should be explained that in most cases when two type barscollide and jam together, obstructing the power mechanism or the keys in a manual machine, the removal of the jamming force very often allows the jammed type bars to be restored by their operating. springs so thatin many cases the relatching of the lever 29 will be all that is required to free thejam.

If a key is held down too long, the vertical arm of hell crank 32 will strike the lower side of finger '35 and rock it on its pivot to extension lBa. When the key is released, the finger 35 will be drawn to the right and snap in front of the vertical arm of bell crank 32. This prevents repeating if the key is held down toolong.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit 0f the invention.

What is claimed is:

l. A power mechanism comprising a toothed main actuator, a lever having .a, connection to a device to be operated, a coupling member movably mounted on said lever, a toothed elementrotatably mounted on said coupling member, yielding means normally restraining rotation of the toothed element and means to move said member to engage said toothed element with said toothed actuator, said yielding means being operative, when movement of said lever is blocked, to permit said toothed element to rotate.

2. A power mechanism for typewriters and other ofiice machines comprising a toothed actuator, a lever having a connection to a device to be operated, a coupling levermounted onthe first lever, a rotary coupling element pivoted on the coupling lever, means to rock the coupling lever to engage the coupling element with the toothed actuator; and means on said coupling lever for normally restraining rotation of said element toenable the actuator to operate the first lever, said means being designed to yield and permit rotation of said element when the first lever is blocked against operation.

3. A power mechanism for typewriters and other ofiice machines comprising a toothed actuator, ale'ver having a connection to a device to be operated, a coupling lever mounted on the first lever, a rotary coupling element pivoted on the coupling lever, means to rock the coupling lever to engage the coupling element with the toothed actuator; and yielding means engaging said element to normally hold said element immobile to enable said actuator to operate said first lever through said coupling lever and permitting'said element to turn when the first lever is not freeto operate the device tobe operated.

4. A power mechanism for typewriters and other ofice machines comprising a toothed actuator, a lever having a connection to a device to be operated, a coupling lover mounted on the first lever, a rotary coupling element pivoted on the coupling lever, means to rock the coupling lever to engage the coupling element with the toothed actuator; and spring means engaging said coupling element to yieldingly restrain rotation thereof to enable the actuator to operate the first lever through said coupling lever but capable of yielding sufliciently to permit rotation of said element when said first lever is restrained. from normal operation.

5. A power mechanism comprising a toothed actuator, a rockable support having a connection to a mechanism to be operated, an arm-pivotally mounted on said support, releasable means to hold said arm in an: inactive position in which ,75 the mechanism to be operated is idle, a star wheel rotatably mounted on said arm, a spring carried by said arm and holding said star wheel against rotation; and means rendered effective, when the releasable means is operated, to rock said arm to engage said start wheel with said toothed actuator, said actuator, when said star wheel is engaged therewith, rocking said support and operating the connected mechanism, said spring, when the connected mechanism is held against operation, permitting said star wheel to turn harmlessly.

6. A power mechanism comprising a main actuator having a power stroke from a coupling position to an uncoupling position, a coupling member having a motion between a normal idle position and an uncoupling position and having a connection to a device to be operated, a coupling element mounted on said member and having a portion engageable with said actuator in its coupling position, said portion being movable relative to said member in the direction of the power stroke of said actuator; means normally restraining said relative movement and enabling the actuator to move said member from its normal idle position to uncoupling position, said restraining means permitting said relative movement of said coupling element when said coupling member is blocked from moving to its uncoupling position, means to move said coupling member to engage the coupling element with said actuator, and means to uncouple said element from said actuator in the uncoupling position thereof.

7. A power mechanism comprising a main actuator having a power stroke from a coupling position to an uncoupling position, a coupling member having a motion between a normal idle position and an uncoupling position and having a connection to a device to be operated, a coupling element mounted on said member and having a portion engageable with said actuator in its coupling position, said portion being movable relative to said member in the direction of the power stroke of said actuator; spring means normally restraining said relative movement and enabling the actuator to move said member from its normal idle position to uncoupling position, said restraining means permitting said relative movement of said coupling element when said coupling member is blocked from moving to its uncoupling position, means to move said coupling member to engage the coupling element with said actuator, and means to uncouple said element from said actuator in the uncoupling position thereof.

8. A power mechanism comprising a main actuator having a power stroke from a coupling position to an uncoupling position, a coupling member having a motion between a normal idle position and an uncoupling position and having a connection to a device to be operated, a coupling element pivotally mounted on said member and having a portion engageable with said actuator in its coupling position, said element being pivotally movable relative to said member in the direction of the power stroke of said actuator;

means normally restraining said pivotal relative movement and enabling the actuator to move said member from its normal idle position to uncoupling position, said restraining means permitting pivotal movement of said coupling element when said coupling member is blocked from moving to its uncoupling position, means to move said coupling member to engage the coupling element with said actuator, and means to uncouple said element from said actuator in the uncoupling position thereof.

9. A power mechanism comprising a main actuator having a power stroke from a coupling position to an uncoupling position, a coupling member having a motion between a normal idle position and an uncoupling position and having a connection to a device to be operated, a coupling element pivotally mounted on said member and having a portion engageable with said actuator in its coupling position, said element being pivotally movable relative to said member in the direction of the power stroke of said actuator; spring means normally restraining said pivotal relative movement and enabling the actuator to move said member from its normal idle position to uncoupling position, said restraining means permitting said pivotal movement of said cou-- pling element when said coupling member is blocked from moving to its uncoupling position, means to move said coupling member to engage the coupling element with said actuator, and means to uncouple said element from said actuator in the uncoupling position thereof.

10. A power mechanism comprising a main actuator having a power stroke from a coupling position to an uncoupling position, a coupling member having a motion between a normal idle position and an uncoupling position and having a connection to a device to be operated, a star wheel rotatably mounted on said member and having a portion engageable with said actuator in its coupling position, said star wheel being rotatable in the directionof the power stroke of said actuator; means normally restraining said rotation and enabling the actuator to move said member from its normal idle position to uncoupling position, said restraining means permitting rotation of said star wheel when said coupling member is blocked from moving to its uncoupling position, means to move said coupling member to engage the star wheel with said actuator, and means to uncouple said star wheel from said actuator in the uncoupling position thereof.

RICHARD V. REPPERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,079,425 Reppert May 4, 1937 2,411,496 I-Iandley Nov. 19, 1946 

